The present invention pertains to imaging systems and, more particularly, to an imaging system having a 360-degree field of view (FOV).
In certain applications, it is desirable for an imaging system to have a large (FOV) in order to provide as much information as possible about the surroundings of the imaging system. For example, underwater remotely operated vehicles (ROVs) are used to accomplish underwater tasks in a variety of fields. The difficulty of these tasks is increased due to the fact that the operator is situated at a remote location, thereby limiting the operator's awareness of the ROV's surroundings. Accordingly, ROVs typically include one or more cameras. When a single camera is used, the camera pans and tilts to show different areas around the ROV. However, this still provides only a relatively small FOV at any given instant and either: 1) requires that the ROV be piloted at the same time the camera is adjusted; or 2) introduces a delay in which piloting ceases while the camera is adjusted. Using multiple cameras increases the cost and complexity of the system. Also, regardless of whether a single camera is used or multiple cameras are used, the camera arrangement may not provide a single, panoramic view, thereby requiring increased effort on the part of the operator to assess the ROV's surroundings.
Furthermore, for an underwater imaging system, the transition between air and water causes issues due to refraction. As is known in the art, refraction is the change in direction of propagation of a wave (e.g., light) due to a change in its transmission medium (e.g., air or water). When light moves between two transmission media, the light is bent, which causes distortion in a scene that includes multiple transmission media (and, hence, in an image generated from the scene). Additionally, when an imaging system is used underwater, it is important that the components of the system be protected from water. Therefore, the imaging system usually includes a transparent window that at least partially encloses the system's components. It is desirable that such a window be securely coupled to the rest of the system, provide a watertight seal and not obstruct the imaging system's FOV.
Accordingly, there is a need in the art for an imaging system that provides a large FOV, eliminates problems due to refraction and includes a window having the desired properties.